Lifting-jack



(No Model.)

T. J. JENNE & 0. s. HARMON.

LIFTINGYJAUK.

No. 245,634. Patented Aug 16,1881

lfa

UNITED STATES PATENT OFFICE.

THOMAS J. JENNE, CHICAGO, AND CHARLES S. HARMON, OF BLUE ISLAND, ILL.;SAID JENNE ASSIGNOR TO SAID HARMON; SAID HARMON ASSIGNOR OF ONE-FIFTH TOGEORGE W. STANFORD, AND ON E-EIGHTH OF HIS RE- MAINING RIGHT TO EDWIN B.SMITH, BOTH OF CHICAGO, ILLINOIS.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 245,634, dated August16, 1881.

Application filed January 17, 1881. (N model.)

To all whom it may concern:

Be it known that we, THOMAS J. JENNE and CHARLES S. HARMoN, citizens ofthe United States, residing at Chicago and Blue Island,

respectively, in thecoun tyofCook and State of Illinois, have inventedcertain new and useful Improvements in Lifting-Jacks; and we herebydeclare the following to be a full, clear, and exact descriptionthereof, reference being had to IO the accompanying drawings, of whichFigure l is a front elevation of our device; Fig.2, aside elevation ofthe same, and Figs. 3, 4, 5, 6, 7, and 8 detail views.

Our present invention relates to certain improvements uponaformerinventionin liftingjacks, for which Letters Patent of the UnitedStates, No. 192,831, were granted to Thomas J.Jenne,July 10,1877, ourobject beingto both simplify and strengthen the device, better adaptingit to railway use and lifting heavy weights.

To this end our invention consists, first, in the particularconstruction of the standard which we now employ; secondly, in the con-2 5 struction of the journal-caps, which we use in combination with thestandard and certain attendant parts to resist the strain exerted by thelever; thirdly, in the general combination of parts comprising ourdevice; and, fourthly,

0 in the specific construction of the lever which we employ, all ashereinafter more fully set forth.

In the drawings, A is astandard, having a base-plate, w, and having itsupper portion bifurcated, as shown, to produce the twonpright arms n.These arms are provided with lugs to projecting forward from their upperends to prevent external objects from coming into contact with theworking parts. The front face of the standard is provided with twolongitudinal flanges, t, extending from the baseplate to to the arms,and serving as guides for the bar B. This bar is provided with a foot,.9, at its lower end, and is screw-threaded at its 4 5 upper end toreceive the nut 1'. It is retained within the guides t by means of thecross-plate g, which is cast with the standard. The bar is insertedthrough a slot in the base-plate, between the guides t, and afterinsertion the slot is closed by a sliding plate,p, the sides of the slotand edges of the plate beingsuitably dovetailed together to prevent theremoval of the said plate in any other way than by drawing it out.

0 is a collar, through which the bar passes at the upper end of thestandard, and which is provided with trunnions o resting in journals inthe tops of the upright arms 1;. These trunnions also form the fulcrumof the lever D. The caps 11. of the journals are fitted to the arms o bymeans of dovetailed projections m, which fit into recesses ofcorresponding form in the upper ends of the arms o. The caps are placedin position by forcing the projections laterally into the recesses fromthe outside, where they are obviously held firmly in position againstany upward pressure. This method of securing the caps is preferable tofastening them with bolts, both because it enables the cap to resist agreater upward strain, and because it is more readily applied. We preferto flatten a part of the lower face of each trunnion 0 where it entersthejournals, as shown in Fig. 7, to preventitfrom turning under a severestrain.

E and E are two friction collars or pawls sliding upon the lifting-bar,and F is a clevis connecting the hook lof the upper pawl with the shortarm of the lever. We prefer to form this clevis ot' cast-steel, and witha web, 70, to give it the greatest possiblev strength. The openingsthrough the centers of the pawls or collars E and E are somewhat largerthan the bar B, which passes through them, and are both oblique, butadapted to incline in contrary directions with respect to each otherwhen the pawls are in position, whereby they serve to gripe the baralternately, the upper one to raise it by means of the clevis and lever,and the lower one to retain it while the upper one 0 is being loweredfor a fresh gripe.

To permit the bar to descend from any point it is obvious that both barsor collars must be so tilted as to bring the walls of their openingsinto avertical position, when the bindingeeases and the bar readilyslips through. For the purpose of thus tilting the lower or retainingpawl, E, we provide it with a lip, t, designed to be operated by thefoot or hand. The upper one, E, is tilted automatically when the handleis raised to a sutficient height by bringing up against the upper edgeof a plate, h, connecting the arms 1; at the rear of the bar B. WVeprefer to have this plate extend downward nearly to the projection iupon the lower pawl, as shown in Fig. 1, in order to resist any possibletendency of the said pawl to lift with the bar.

It is sometimes desirable to have the bar B descend gradually instead ofsuddenly, and for this purpose it is only necessary to.loosen the pawlsalternately instead of simultaneously. Thus, for illustration, the pawlE being in position to bind the bar, the pawl E is loosened by tiltingitand the handle lowered. The pawl E is then allowed to act, the pawl Etilted, and the handle raised, thus lowering the load, care being taken,however, not to lower the pawl E far enough to strike against the plateh before the pawl E is left free to act, as this would loosen the twosimultaneously and allow the bar to drop. The pawl E is then again letgo, the pawl E loosened, and the operation repeated as before. Tofacilitate this operation we provide the pawl E with the thumb-piece 9.

To enable the pawls E and E to withstand the severe strain to which theyare subjected in raising heavy weights without at the same timeimpairing the gripe by making the length of the oblique opening throughwhich the bar B passes too great, they may be constructed asrepresentedin Fig. 4that is to say, of the requisite thickness forstrength, but with the oblique opening chamfered on its upper and loweredges, as indicated at h.

The lever l) is formed in two partsviz., the inner part or socket, andthe outer part or handlee-the two being separable from each other. Thesocket is bifurcated and the separate branches fulcrumed on oppositesides of the bar B, as shown. It is formed of two bars,f, firmlyconnected, about midway between the fulcrum and the end, by means of abolt, 0, passing through both bars, and also through a cored lug, b,cast upon one of said bars. Thus while the bolt 0 holds the barstogether, the lug maintains them at a proper distance apart to permitthe entrance of the handle 0. The inner end of the handle is notched, asindicated by the dotted lines in Fig. 2, to engage with the lug b whenit is inserted. The outer end of the socket is provided with a collar,G, formed in two parts, a and a. The male part a is provided with lugsb, which fit into shoulders in the female a, and the two parts aresecured together by bolts or rivets c.

The standard is provided with hinged handles H, to admit of its beingreadily carried and adjusted.

If desired, two clevises, as shown in the former Letters Patent aboy ereferred to, may be used instead of one, causing the lever to operate toraise the bar when moved in either direction; but for great weights itis preferable to have the lever operate only by a downward pressure, asmuch greater physical exertion is necessary to produce an equal effectwith an upward pressure.

By making the above device sufficiently large it may be used withadvantage as a pile-driver.

What we claim as new, and desire to secure by Letters Patent, is-- 1.The standard A, comprising the slotted base 10, provided with thesliding plate 1), guides t, cross-plate q, and arms t, provided with thecross-plate h and recesses at their tops to form journals for thetrunnions o, substantially as described.

2. In combination with the arms '11 of the standard A, recessed to formjournals for the trunnions 0, the caps it, provided with dovetailedprojections m, fitting corresponding recesses in the said arms,snbstantially'as described.

3. The combination of the standard A, provided with the arms 1;, havingthe cross-plate h, collar 0, having the trunnions 0, working in journalsat the tops of the arms o, lifting-bar B, passing through the collar 0,lever D, working upon the trunnions 0 as a fulcrum, friction collars orpawls E and E upon the bar B, and clevis F, connecting the short arm ofthe lever D with thepawl E, substantially as described.

4. The combination of the bars f, working upon the trunnions o as afulcrum, cored lug b upon one of said bars, bolt 0 passing through bothbars, and also through said lug, and collar G, comprising the male parta, provided with projections b and female part a, having shoulders toreceive the said projections, said parts being held together by bolts orrivets c, substantially as and for the purpose described.

THOMAS J. JENNE. CHARLES S. HARMON.

In presence of- P. C. DYRENFORTH, DOUGLAS DYRENFORTH.

IOC

